Thread-controlling mechanism for sewing machines



April 2 3 J. R. MOFFATT 1,756,655

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Aug. 29. 1928Patented Apr. 29, 1930 ice JAMES R. MOFFATT, OF CHICAGD, ILLINOIS,ASSIGNOR '10 UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS THREAD-CONTROLLING MECHAN'ISM FOR SEWINGMACHINES Application filed August 29, 1928.

The invention relates to new and useful improvements in threadcontrolling mechanisms for sewing machines, and more particularly to thethread guiding mechanism used in connection with a rotary threadcontrolling element. 7

An object of the invention is to provide a thread guiding mechanism usedin conjunction with a rotary thread controlling element having laterallyprojecting thread engaging cam faces, which thread guiding mechanismincludes open thread eyes so that said thread guides may be readilythreaded without mov ing the same to render them accessible.

A further object of the invention is to provide a thread guidingmechanism of the above type wherein the thread guides and the cast-oftare all mounted on one supporting member adapted to be adjusted in adirection circumferentially of the axis of rotation of the threadcontrolling element.

In the drawings Figure 1 is a plan view of a portion of a sewing machineembodying the improvements.

Fig. 2 is a sectional view on the line 2-2 through a portion of thethread controlling element and showing the supporting bracket for thethread guides and cast-ofl in edge view.

Fig. 3 is a sectional View on the line 33 of Fig. 1.

Fig. 4 is a perspective view of the supporting segment for the threadguides showing thethread guides and the cast-0E and stripper mountedthereon.

The invention is directed to a thread controlling mechanism of the typewherein there is a rotating thread controlling element having laterallyprojecting cylindrical flanges radially spaced from each other and withtheir free edges shaped to provide thread take-up cams. Associated withthis thread controller is a thread guiding mechanism which includes anouter thread guide located outside of the periphery of the threadcontrolling element, and an inner thread guide located inside of theperiphery of the flanges. The inside thread guide is carried by asegment bracket and is provided with a project- 50 ing arm on which theouter thread guide is Serial No. 362,803.

mounted. On the arm carrying the outer thread guide the cast-off andthread retainer are mounted. Both the inner and the outer thread guidesinclude eyes with a slot leading therefrom andthe face of the supportingmemher for each thread guide is curved so that when the thread is laidagainst said curved faces and drawn on it will slide along both of thecurved faces through the slots and into the eyes. Thus it is that thethread guiding mechanism is self-threading. I

Referring more in detail to the drawings, the invention is shown asapplied to a sewing machine having a cylindrical supporting member 1 inwhich is mounted a rotating shaft 2. This rotating shaft-2 carries therotating thread controllingelement 3. Said rotating thread controllingelement 3 is provided with an outer cylindrical flange 4 and an innercylindrical flange 5. These flanges are radially spaced from each other.The free edges of the flanges are cam shaped and these are the threadcontrolling cams which in succession engage the threads for taking upand giving up said threads. is mounted on the shaft and this sleeve isheld from rotation with the shaft so that it is stationary. Attached tothis sleeve is a segment bracket 7, which is secured to the sleeve by ascrew 8 passing through a slot in the bracket and threaded into thesleeve. Thus it is that the segment bracket may be ad justedcircumferentially on the sleeve about the center of the shaft;

Projecting outwardly from this segment bracket 7 is an arm 9. This arm 9is provided with a thread eye 10 and a slot 11 leading to the eye. Thereis also a curved surface 12. Just beyond the eye from the curved surface12 there is a shoulder 13. The thread engaging curved face 12 will slidealong the same and pass through the slot 11 into the thread eye 10. Alsoattached to this arm 9 is a second arm 13*. This arm projects overtherotating controlling element while the arm 9 is inside thereof so thatthe thread eye 10 is radially disposed. within the periphery of theinner thread controlling flange 5. The arm 18 is provided with a curvedface 14 which leads into an A sleeve '6- gles to the axis of the shaft.

between the nipper springs 17.

guide, and this thread eye is located beyond the periphery of theouterthread controlling flange 4; The thread is led from the supplythrough a guiding passage 16 and thence The thread is indicated at Z inthe drawings. After the thread leaves the nipper springs ifit is placedagainst the curved faces 12 and 14 and drawn toward the front of themachine it will slide along these curved surfaces and enter the eyes 10and 16. Thus it is that the thread guides o are self-threading as allthat is necessary is to lay the thread against the curved faces and pullon it and it will enter the eyes.

Attached to the arm 13 is a forwardly pro-- jecting member 18, which isprovided with a straight face 19 lying in a plane at right an- Alsocarried by this projecting member 18 is a cast-off arm 20, which lies inthe space between the cylindrical flanges controlling the thread Thiscast-off member engages the thread and casts it off from the cam faces,while the retainer 19 puts a slight drag on the thread and retards thethread as it is given up to the stitching element with which saidcontroller is associated. This thread controller'with its cast-off andretainer per se form no part of the present invention. They are similarin mode of operation to the cast-off and retainer disclosed in myco-pending application Serial No. 130,954, filed August 23, 1926. Thepresent invention is directed particularly to the manner of mounting thethread guides and the construction thereof whereby they areself-threading. 7

It is obvious that minor changes in the details of construction may bemade withoutdeparting from the spirit of the invention as set forth-inthe appended claims.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is

1.. A thread controller for sewing machines comprising a rotating shaft,a thread controlling element mounted on said shaft and having avlaterally projecting flange, thread guides located Within and withouttheperiphery of the flange, an arm for each thread guide, said armsextending laterally beyond the flange and connected at their outer ends,each arm having a curved face leading through a slot to a guide eyeforming. the thread guide, and means for supporting said arms. 7 V

2. A thread controlling for sewing machines comprising a rotating shaft,a thread controlling element mounted on said shaft and having laterallyprojecting cylindrical flange, thread guides located within and withoutthe periphery of the flange, an arm for each thread guide extendinglaterally be- 'ycnd the flange and connected at their outer ends, and astationary supporting bracket to which the arm of the inner thread guideis connected, said arms having curved faces leading through slots to theguide eyes form ing eyes forming the thread guides. I

3. A thread controller for sewing machines comprising a rotating shaft,a thread. ccntrolling element mounted .on said shaft. and having alaterallyprojecting cylindrical flange, thread guides located within andwith out the periphery-cf the flange, anarm foreach thread guideextending laterally beyond the flange and connected at their outer ends,a stationary supporting bracket to which the arm of the inner threadguide; is connected, said,

arms having curved faces leading through slots to the guide eyes formingthe thread guides, a member projecting from the arm carrying the outerthread guide, said member being disposed. relative to the flange of thethread controlling element and shaped so as to provide a cast-off forcasting the thread ofl" from the controlling cam formed on said flange,and a retainer for retaining the thread after it is cast from thecontrollingcam.

4. A thread controller for sewing machines comprising a rotating shaft,a threaded controlling element secured to the shaft and having radiallyspaced laterally projecting cylindrical flanges, thread guides locatedwith in and without the, periphery of the flanges,

a stationary sleeve on the shaft extending underneath the flanges, asegmental bracket see cured to said stationary sleeve, an arm for theinner thread guide vrigidlyconnectedto said bracket, and an arm for theouter thread guide attached to the arm for the inner thread guideata'point beyond saidlflangeasaid arms having curved faces leadingthrough slots to eyesforming the thread guides whereby said threadguides are self-threading.

' 5. A thread controller for sewing machines 7 comprising a rotatingshaft, a thread controlling element secured to the shaft and havingradially spaced laterally projecting cylindrical flanges,.thread guideslocated within and without the peripheryyof theflanges, a stationarysleeve on the shaft extending under-, A

neath the flanges,a segmental bracket secured to said stationary sleeve,an arm for the inner thread guide rigidly connected to said bracket,anarm for the outerthread guide attached to the arm forthe inner threadguide at a point beyond said flanges,.said arms having curved facesleading through slots to eyes forming the thread guides whereby saidthread. guides are self-threading and, a member secured to the armcarrying the outer thread'guide, said member having a portion projectingbetween said flanges and provided with an inclined face for strippingthe thread from the take;

up cams formed on said flanges.

6. A thread'controller. for sewing machines comprising a rotating shaft,athread controlling element secured to the shaft and having radiallyspaced laterally projecting cylindrical flanges, thread guides locatedWithin and Without the periphery of the flanges, a stationary sleeve onthe shaft extending underneath the flanges, a segmental bracket securedto said stationary sleeve, an arm for the inner thread guide rigidlyconnected to said bracket, an arm for the outer thread guide attached tothe arm for the inner thread guide at a point beyond said flanges, saidarms having curved faces leading through slots to eyes forming thethread guides Whereby said thread guides are self-threading, and amember secured to the arm carrying the outer thread guide, said memberhaving a portion projecting between said flanges and provided with aninclined face for stripping the thread from the take-up cams formed onsaid flanges, said member also having a thread retaining face adapted tocooperate with the flanges in the retaining of the thread after it iscast from the take-up cams.

In testimony whereof, I affix my signature.

JAMES R. MOFFATT.

